In the production of electronic machines and apparatus including a computer, and semiconductors such as an IC and LSI constituting the hearts thereof, a purified chamber called a clean room is necessary for the prevention of discharge breakdown due to static electricity and the adhesion of dust, and such rooms have recently being employed increasingly.
For the walls and floor of the clean room are being employed antistatic materials, and a silicone-type sealant and the like have been used for the sealing of the joints between the antistatic materials. However, since those sealed joint portions obtained from such a silicone-type sealant are electrostatically charged, causing the dust to adhere thereto, electroconductive sealants such as a carbon or metallic type sealant are replacing silicone-type sealants.
However, there is a problem that the color of such an electroconductive sealant does not match with that of the walls and floor and spoils the appearance of the clean room, because the electroconductive sealant is generally a carbon or metallic type and has a dark shade of color such as black or brown in contrast to the white or light and bright color of the walls and floor. Further, from the standpoint of the prevention of dust adhesion, the high electroconductivity of the carbon-type or metallic-type electroconductive sealant is unnecessary, and intermediate electroconductivity, i.e., semiconductivity, is sufficient. Not only is such high electroconductivity unnecessary, but also there is a fear that the sealing with a sealant having too high an electroconductivity is dangerous because of a possible discharge breakdown.